From the Hertz rewards conditions:
Earn and redeem Hertz Gold Plus Rewards points at participating locations in the United States, Canada, Puerto Rico, St. Thomas U.S. Virgin Islands, Australia, New Zealand, the United Kingdom, France, Germany, Norway, Denmark, Sweden, Finland, Ireland, Italy, Spain, Belgium, Luxembourg and the Netherlands. Rentals in Switzerland will earn points, but members are unable to redeem rewards points there.
Were any of your international rentals outside of the countries listed above?